The present invention relates to methods and apparatus for transferring and positioning bulky cargo relative to a storage area. More particularly, the present invention relates to methods and apparatus for loading and unloading bulky cargo onto a flatbed storage area such as the platform of a truck. Although not necessarily limited thereto, the present invention is particularly useful for loading and unloading cable reels as are employed by utility companies and the like onto a transporting vehicle and further for controlling the positioning and feeding or winding of cable relative to those reels.
Bulky and awkward cargo which cannot be lifted manually frequently must be transferred and positioned from a surface such as the ground, a roadway or the like to a platform. Wherever the transfer and location of the cargo is effected at a single location, cranes, derricks or similar devices can be located to effect the transfer and positioning results. However, with the mobility of vehicles for cargo carrying purposes and the diverse locales in which unloading, loading and transferring must be performed, it is impossible to resort to cranes or derricks or at least undesirable to modify the vehicle so as to include such apparatus. Thus, various efforts have been directed towards developing relatively self-contained assemblies on the vehicle for loading, unloading and otherwise handling such awkward cargo. Typically, such systems employ some arrangement on the cargo itself for simplifying its handling such as handles, spindles or other grippable structure for cooperating with the vehicle mechanism to allow positioning and transfer control.
The transfer and handling problems have been attacked for trash or refuse containers by a wide variety of arrangements. For instance, U.S. Pat. No. 2,121,121 by Dempster employs a container gripping framework along with a chain driven and scaffold mounted configuration for lifting the container and tilting it for dumping when it reaches the height of the scaffold. A somewhat similar approach is shown in U.S. Pat. No. 3,732,997 by Reavis et al. which likewise includes an enveloping gripping assembly for securing a handlebar on the container with the entire chain-driven elevator mechanism being outwardly pivotable for dumping purposes. Other refuse container apparatus has been suggested using pivoted lift arms which are coupled to linear hydraulic actuators such as in U.S. Pat. Nos. 3,012,684 by Sexton et al., 3,027,028 by Brown, 3,167,195 by Jensen et al. and 3,702,662 by Davieau. Jensen et al. engages the container by outwardly extending arms and retaining nubs whereas the Sexton et al., Brown and Davieau devices employ various arrangements of clasping gripper arrangements for spindles on the container.
Somewhat different approaches have been suggested for problems associated with transferring bulky cable reels relative to a transport vehicle platform. In this regard, one arrangement for loading a cable reel is shown in U.S. Pat. No. 3,091,413 by Leithiser wherein the cable reel is mounted between a pair of generally triangular shaped side arm assemblies which are thence pivoted so as to load and unload the reel between a vertically oriented position and the surface. Yet another arrangement is suggested in U.S. Pat. No. 2,867,390 by Anrig wherein an arrangement of pivotal side arms are interconnected with a winch cable so that the cable can be pivoted onto guide tracks. Anrig suggests loading more than one reel onto the trailer by rolling the reels into positions along a vertical frame where they can be clamped and thence attaching another reel to the cable controlled pivotal assembly. Services such as those of Anrig and Leithiser are of little value for situations wherein it is necessary to load and unload reel devices between positions which require the lifting mechanism to accommodate pivoting which even approaches 180.degree.. The prior art devices which can accommodate such pivotal loading and unloading through approximately 180.degree. have used offset linkages such as those suggested in U.S. Pat. Nos. 3,165,214 by Young and 3,325,118 by Hall. Young and Hall type mechanisms utilize pivotally mounted but linearly operable hydraulic rams coupled to offset pivot linkages in order to obtain rotation of approximately 180.degree..
Despite the various developments in the prior art, there has been a continuing need for apparatus and methods which can allow loading of cargo through rotation of approximately 180.degree. without resort to offset linkages. Further, there has been a continuing need for apparatus and methods which can accommodate handling and positioning of awkward cargo from positions between a surface and multiple locations relative to a vehicle platform. Still further, there has been a continuing need for a method and apparatus particularly useful for controlled winding and payout of cables on a transport vehicle platform after loading thereon. Such devices must be configured with minimal, reliably operable components for dependable long-term and heavy duty usage.